Prevent Transparent from casting Shadows
If you want to hide something completely from your render then use this method as it should give better performance.

In the outliner, there is a little picture of a camera next to each object. clicking it so it is disabled means that the object will not be rendered at all, which sounds like what you want.

This will only apply in the final render and not the preview render unless you set the view to be render only ('n'panel -> display -> only rendered or something like that).